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Vasudevan S, Senapati S, Pendergast M, Park PSH. Aggregation of rhodopsin mutants in mouse models of autosomal dominant retinitis pigmentosa. Nat Commun 2024; 15:1451. [PMID: 38365903 PMCID: PMC10873427 DOI: 10.1038/s41467-024-45748-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 02/01/2024] [Indexed: 02/18/2024] Open
Abstract
Mutations in rhodopsin can cause it to misfold and lead to retinal degeneration. A distinguishing feature of these mutants in vitro is that they mislocalize and aggregate. It is unclear whether or not these features contribute to retinal degeneration observed in vivo. The effect of P23H and G188R misfolding mutations were examined in a heterologous expression system and knockin mouse models, including a mouse model generated here expressing the G188R rhodopsin mutant. In vitro characterizations demonstrate that both mutants aggregate, with the G188R mutant exhibiting a more severe aggregation profile compared to the P23H mutant. The potential for rhodopsin mutants to aggregate in vivo was assessed by PROTEOSTAT, a dye that labels aggregated proteins. Both mutants mislocalize in photoreceptor cells and PROTEOSTAT staining was detected surrounding the nuclei of photoreceptor cells. The G188R mutant promotes a more severe retinal degeneration phenotype and greater PROTEOSTAT staining compared to that promoted by the P23H mutant. Here, we show that the level of PROTEOSTAT positive cells mirrors the progression and level of photoreceptor cell death, which suggests a potential role for rhodopsin aggregation in retinal degeneration.
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Affiliation(s)
- Sreelakshmi Vasudevan
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Subhadip Senapati
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
- Prayoga Institute of Education Research, Bengaluru, KA, 560116, India
| | - Maryanne Pendergast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Paul S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA.
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2
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Peng H, Ramadurgum P, Woodard DR, Daniel S, Nakahara E, Renwick M, Aredo B, Datta S, Chen B, Ufret-Vincenty R, Hulleman JD. Utility of the DHFR-based destabilizing domain across mouse models of retinal degeneration and aging. iScience 2022; 25:104206. [PMID: 35521529 PMCID: PMC9062244 DOI: 10.1016/j.isci.2022.104206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 02/16/2022] [Accepted: 04/04/2022] [Indexed: 11/25/2022] Open
Abstract
The Escherichia coli dihydrofolate reductase (DHFR) destabilizing domain (DD) serves as a promising approach to conditionally regulate protein abundance in a variety of tissues. To test whether this approach could be effectively applied to a wide variety of aged and disease-related ocular mouse models, we evaluated the DHFR DD system in the eyes of aged mice (up to 24 months), a light-induced retinal degeneration (LIRD) model, and two genetic models of retinal degeneration (rd2 and Abca4−/− mice). The DHFR DD was effectively degraded in all model systems, including rd2 mice, which showed significant defects in chymotrypsin proteasomal activity. Moreover, trimethoprim (TMP) administration stabilized the DHFR DD in all mouse models. Thus, the DHFR DD-based approach allows for control of protein abundance in a variety of mouse models, laying the foundation to use this strategy for the conditional control of gene therapies to potentially treat multiple eye diseases. Destabilizing domains (DDs) confer conditional control of ocular protein abundance The DHFR DD is effectively turned over and stabilized in aged mouse’s retina DHFR DDs perform well in environmental and genetic retinal degenerative models
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3
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Gurdita A, Nickerson PEB, Pokrajac NT, Ortín-Martínez A, Samuel Tsai EL, Comanita L, Yan NE, Dolati P, Tachibana N, Liu ZC, Pearson JD, Chen D, Bremner R, Wallace VA. InVision: An optimized tissue clearing approach for three-dimensional imaging and analysis of intact rodent eyes. iScience 2021; 24:102905. [PMID: 34430805 PMCID: PMC8374524 DOI: 10.1016/j.isci.2021.102905] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/28/2021] [Accepted: 07/21/2021] [Indexed: 02/05/2023] Open
Abstract
The mouse eye is used to model central nervous system development, pathology, angiogenesis, tumorigenesis, and regenerative therapies. To facilitate the analysis of these processes, we developed an optimized tissue clearing and depigmentation protocol, termed InVision, that permits whole-eye fluorescent marker tissue imaging. We validated this method for the analysis of normal and degenerative retinal architecture, transgenic fluorescent reporter expression, immunostaining and three-dimensional volumetric (3DV) analysis of retinoblastoma and angiogenesis. We also used this method to characterize material transfer (MT), a recently described phenomenon of horizontal protein exchange that occurs between transplanted and recipient photoreceptors. 3D spatial distribution analysis of MT in transplanted retinas suggests that MT of cytoplasmic GFP between photoreceptors is mediated by short-range, proximity-dependent cellular interactions. The InVision protocol will allow investigators working across multiple cell biological disciplines to generate novel insights into the local cellular networks involved in cell biological processes in the eye. InVision is an optimized tissue clearing protocol for the rodent eye InVision can be used to study a wide variety of physiological processes in the eye Material transfer between transplanted and host photoreceptors is spatially correlated
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Affiliation(s)
- Akshay Gurdita
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Philip E B Nickerson
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - Neno T Pokrajac
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Arturo Ortín-Martínez
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - En Leh Samuel Tsai
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - Lacrimioara Comanita
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - Nicole E Yan
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - Parnian Dolati
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Nobuhiko Tachibana
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - Zhongda C Liu
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada
| | - Joel D Pearson
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Danian Chen
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada.,Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Rod Bremner
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
| | - Valerie A Wallace
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
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Huang J, Xian B, Peng Y, Zeng B, Li W, Li Z, Xie Y, Zhao M, Zhang H, Zhou M, Yu H, Wu P, Liu X, Huang B. Migration of pre-induced human peripheral blood mononuclear cells from the transplanted to contralateral eye in mice. Stem Cell Res Ther 2021; 12:168. [PMID: 33691753 PMCID: PMC7945672 DOI: 10.1186/s13287-021-02180-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 01/20/2021] [Indexed: 11/26/2022] Open
Abstract
Background Retina diseases may lead to blindness as they often afflict both eyes. Stem cell transplantation into the affected eye(s) is a promising therapeutic strategy for certain retinal diseases. Human peripheral blood mononuclear cells (hPBMCs) are a good source of stem cells, but it is unclear whether pre-induced hPBMCs can migrate from the injected eye to the contralateral eye for bilateral treatment. We examine the possibility of bilateral cell transplantation from unilateral cell injection. Methods One hundred and sixty-one 3-month-old retinal degeneration 1 (rd1) mice were divided randomly into 3 groups: an untreated group (n = 45), a control group receiving serum-free Dulbecco’s modified Eagle’s medium (DMEM) injection into the right subretina (n = 45), and a treatment group receiving injection of pre-induced hPBMCs into the right subretina (n = 71). Both eyes were examined by full-field electroretinogram (ERG), immunofluorescence, flow cytometry, and quantitative real-time polymerase chain reaction (qRT-PCR) at 1 and 3 months post-injection. Results At both 1 and 3 months post-injection, labeled pre-induced hPBMCs were observed in the retinal inner nuclear layer of the contralateral (left untreated) eye as well as the treated eye as evidenced by immunofluorescence staining for a human antigen. Flow cytometry of fluorescently label cells and qRT-PCR of hPBMCs genes confirmed that transplanted hPBMCs migrated from the treated to the contralateral untreated eye and remained viable for up to 3 months. Further, full-field ERG showed clear light-evoked a and b waves in both treated and untreated eyes at 3 months post-transplantation. Labeled pre-induced hPBMCs were also observed in the contralateral optic nerve but not in the blood circulation, suggesting migration via the optic chiasm. Conclusion It may be possible to treat binocular eye diseases by unilateral stem cell injection. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02180-5.
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Affiliation(s)
- Jianfa Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Bikun Xian
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.,The Second People's Hospital of Foshan, Foshan, 528000, Guangdong, China
| | - Yuting Peng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.,Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou, 510120, China
| | - Baozhu Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Weihua Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Zhiquan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yaojue Xie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Minglei Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Hening Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Minyi Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Huan Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Peixin Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Xing Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.
| | - Bing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.
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Makino CL, Duda T, Pertzev A, Sharma RK. Experimental Approaches for Defining the Role of the Ca 2+-Modulated ROS-GC System in Retinal Rods of Mouse. Methods Mol Biol 2019; 1753:129-158. [PMID: 29564786 DOI: 10.1007/978-1-4939-7720-8_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our ability to see is based on the activity of retinal rod and cone photoreceptors. Rods function when there is very little light, while cones operate at higher light levels. Photon absorption by rhodopsin activates a biochemical cascade that converts photic energy into a change in the membrane potential of the cell by decreasing the levels of a second messenger, cGMP, that control the gating of cation channels. But just as important as the activation of the cascade are the shut-off and recovery processes. The timing of shutoff and recovery ultimately affects sensitivity, temporal resolution and even the capacity for counting single photons. An important part of the recovery is restoration of cGMP through the action of rod outer segment membrane guanylate cyclases (ROS-GCs) and guanylate cyclase-activating proteins (GCAPs). In darkness, ROS-GCs catalyze the conversion of GTP to cGMP at a low rate, due to inhibition of cyclase activity by GCAPs. In the light, GCAP enhances ROS-GC activity. Mutations in the ROS-GC system can cause problems in vision, and even result in blindness due to photoreceptor death. The mouse has emerged as a particularly useful subject to study the role of ROS-GC because the technology for the manipulation of their genetics is advanced, making production of mice with targeted mutations much easier. Here we describe some experimental procedures for studying the retinal rods of wild-type and genetically engineered mice: biochemical assays of ROS-GC activity, immunohistochemistry, and single cell recording.
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Affiliation(s)
- Clint L Makino
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, USA.
| | - Teresa Duda
- Unit of Regulatory and Molecular Biology, Research Divisions of Biochemistry and Molecular Biology, Salus University, Elkins Park, PA, USA
| | - Alexandre Pertzev
- Unit of Regulatory and Molecular Biology, Research Divisions of Biochemistry and Molecular Biology, Salus University, Elkins Park, PA, USA
| | - Rameshwar K Sharma
- Unit of Regulatory and Molecular Biology, Research Divisions of Biochemistry and Molecular Biology, Salus University, Elkins Park, PA, USA
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Dysli C, Wolf S, Berezin MY, Sauer L, Hammer M, Zinkernagel MS. Fluorescence lifetime imaging ophthalmoscopy. Prog Retin Eye Res 2017; 60:120-143. [PMID: 28673870 PMCID: PMC7396320 DOI: 10.1016/j.preteyeres.2017.06.005] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/19/2017] [Accepted: 06/29/2017] [Indexed: 12/17/2022]
Abstract
Imaging techniques based on retinal autofluorescence have found broad applications in ophthalmology because they are extremely sensitive and noninvasive. Conventional fundus autofluorescence imaging measures fluorescence intensity of endogenous retinal fluorophores. It mainly derives its signal from lipofuscin at the level of the retinal pigment epithelium. Fundus autofluorescence, however, can not only be characterized by the spatial distribution of the fluorescence intensity or emission spectrum, but also by a characteristic fluorescence lifetime function. The fluorescence lifetime is the average amount of time a fluorophore remains in the excited state following excitation. Fluorescence lifetime imaging ophthalmoscopy (FLIO) is an emerging imaging modality for in vivo measurement of lifetimes of endogenous retinal fluorophores. Recent reports in this field have contributed to our understanding of the pathophysiology of various macular and retinal diseases. Within this review, the basic concept of fluorescence lifetime imaging is provided. It includes technical background information and correlation with in vitro measurements of individual retinal metabolites. In a second part, clinical applications of fluorescence lifetime imaging and fluorescence lifetime features of selected retinal diseases such as Stargardt disease, age-related macular degeneration, choroideremia, central serous chorioretinopathy, macular holes, diabetic retinopathy, and retinal artery occlusion are discussed. Potential areas of use for fluorescence lifetime imaging ophthalmoscopy will be outlined at the end of this review.
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Affiliation(s)
- Chantal Dysli
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Mikhail Y Berezin
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Lydia Sauer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Martin S Zinkernagel
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Switzerland.
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7
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Xian B, Zhang Y, Peng Y, Huang J, Li W, Wang W, Zhang M, Li K, Zhang H, Zhao M, Liu X, Huang B. Adult Human Peripheral Blood Mononuclear Cells Are Capable of Producing Neurocyte or Photoreceptor-Like Cells That Survive in Mouse Eyes After Preinduction With Neonatal Retina. Stem Cells Transl Med 2016; 5:1515-1524. [PMID: 27458266 DOI: 10.5966/sctm.2015-0395] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 04/18/2016] [Indexed: 02/07/2023] Open
Abstract
: Adult human peripheral blood mononuclear cells (hPBMCs) exhibit pluripotency in vitro and so may be a valuable cell source for regenerative therapies. The efficacy of such therapies depends on the survival, differentiation, migration, and integration capacity of hPBMCs in specific tissues. In this study, we examined these capacities of transplanted hPBMCs in mouse retina as well functional improvement after transplant. We isolated hPBMCs and preinduced them for 4 days in media preconditioned with postnatal day 1 rat retina explants. Preinduction increased the proportions of hPBMCs expressing neural stem cell, neural progenitor cell, or photoreceptor markers as revealed by immunofluorescent staining, flow cytometry, and quantitative real-time polymerase chain reaction. Preinduced hPBMCs were transplanted into the subretinal space of retinal degenerative slow (RDS) and retinal degeneration 1 (RD1) mice. At 1, 3, and 6 months after transplantation, treated eyes of RDS mice were collected and cell phenotype was studied by immunofluorescent staining. Preinduced hPBMCs survived in the subretinal space; migrated away from the injection site and into multiple retinal layers; and expressed neural stem cell, neuronal, and photoreceptor markers. Finally, we assessed RD1 retinal function after subretinal transplantation and found significant improvement at 3 months after transplantation. The ease of harvesting, viability in vivo, capacity to express neuronal and photoreceptor proteins, and capacity for functional enhancement suggest that hPBMCs are potential candidates for cell replacement therapy to treat retinal degenerative diseases. SIGNIFICANCE This study provides support for the use of peripheral blood mononuclear cells (PBMCs) as a potential source of pluripotent stem cells for treating retinal degeneration. First, this study demonstrated that PBMCs can differentiate into retinal neuron-like cells in vitro and in vivo. Second, some transplanted cells expressed markers for neural progenitors, mature neurons, or photoreceptors at 1, 3, and 6 months after subretinal injection. Finally, this study showed that PBMC transplantation can improve the function of a degenerated retina.
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Affiliation(s)
- Bikun Xian
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Yichi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Yuting Peng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Jianfa Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Weihua Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Wencong Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Min Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Kaijing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Hening Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Minglei Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Xing Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Bing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
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8
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Xue Y, Shen SQ, Corbo JC, Kefalov VJ. Circadian and light-driven regulation of rod dark adaptation. Sci Rep 2015; 5:17616. [PMID: 26626567 PMCID: PMC4667277 DOI: 10.1038/srep17616] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/02/2015] [Indexed: 01/10/2023] Open
Abstract
Continuous visual perception and the dark adaptation of vertebrate photoreceptors after bright light exposure require recycling of their visual chromophore through a series of reactions in the retinal pigmented epithelium (RPE visual cycle). Light-driven chromophore consumption by photoreceptors is greater in daytime vs. nighttime, suggesting that correspondingly higher activity of the visual cycle may be required. However, as rod photoreceptors are saturated in bright light, the continuous turnover of their chromophore by the visual cycle throughout the day would not contribute to vision. Whether the recycling of chromophore that drives rod dark adaptation is regulated by the circadian clock and light exposure is unknown. Here, we demonstrate that mouse rod dark adaptation is slower during the day or after light pre-exposure. This surprising daytime suppression of the RPE visual cycle was accompanied by light-driven reduction in expression of Rpe65, a key enzyme of the RPE visual cycle. Notably, only rods in melatonin-proficient mice were affected by this daily visual cycle modulation. Our results demonstrate that the circadian clock and light exposure regulate the recycling of chromophore in the RPE visual cycle. This daily melatonin-driven modulation of rod dark adaptation could potentially protect the retina from light-induced damage during the day.
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Affiliation(s)
- Yunlu Xue
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Ophthalmology &Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Graduate Program in Division of Biological &Biomedical Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Susan Q Shen
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Pathology &Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Graduate Program in Division of Biological &Biomedical Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Joseph C Corbo
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Pathology &Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Vladimir J Kefalov
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Ophthalmology &Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Chakraborty D, Conley SM, Al-Ubaidi MR, Naash MI. Initiation of rod outer segment disc formation requires RDS. PLoS One 2014; 9:e98939. [PMID: 24897172 PMCID: PMC4045911 DOI: 10.1371/journal.pone.0098939] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/08/2014] [Indexed: 11/23/2022] Open
Abstract
Rod outer segment (OS) morphogenesis involves assembly of flattened discs circumscribed by a hairpin-like rim, however, the role of the rim and rim proteins such as retinal degeneration slow (RDS) and its homologue rod OS membrane protein-1 (ROM-1) in this process remains unclear. Here we show that without RDS, no disc/OS formation occurs, while without rhodopsin, small OS structures form containing aligned nascent discs. In the absence of both rhodopsin and RDS, RDS-associated degeneration is slowed, and ROM-1 is stabilized and trafficked to the OS. These animals (rho-/-/rds-/-) exhibit OSs slightly better than those lacking only RDS, but still without signs of disc formation. These results clearly demonstrate that OS morphogenesis is initiated by RDS-mediated rim formation, a process ROM-1 cannot recapitulate, with subsequent disc growth mediated by rhodopsin. The critical role of RDS in this process helps explain why photoreceptors are so sensitive to varied RDS levels, and why mutations in RDS cause debilitating retinal disease.
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Affiliation(s)
- Dibyendu Chakraborty
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Shannon M. Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Muayyad R. Al-Ubaidi
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Muna I. Naash
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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10
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Wang J, Zhang N, Beuve A, Townes-Anderson E. Mislocalized opsin and cAMP signaling: a mechanism for sprouting by rod cells in retinal degeneration. Invest Ophthalmol Vis Sci 2012; 53:6355-69. [PMID: 22899763 DOI: 10.1167/iovs.12-10180] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE In human retinal degeneration, rod photoreceptors reactively sprout neurites. The mechanism is unknown in part because of the paucity of animal models displaying this feature of human pathology. We tested the role of cAMP and opsin in sprouting by tiger salamander rod cells, photoreceptors that can produce reactive growth. METHODS In vitro systems of isolated photoreceptor cells and intact neural retina were used. cAMP signaling was manipulated with nucleotide analogues, enzyme stimulators, agonists for adenosine and dopamine receptors, and the opsin agonist, β-ionone. Levels of cAMP were determined by radioimmunoassay, and protein levels by Western blot and quantitative immunocytochemistry. Neuritic growth was assayed by image analysis and conventional and confocal microscopy. RESULTS cAMP analogues and stimulation of adenylyl cyclase (AC) directly or through G-protein-coupled receptors resulted in significant increases in neuritic growth of isolated rod, but not cone, cells. The signaling pathway included protein kinase A (PKA) and phosphorylation of the transcription factor cAMP response element-binding protein (pCREB). Opsin, a G-linked receptor, is present throughout the plasmalemma of isolated cells; its activation also induced sprouting. In neural retina, rod sprouting was significantly increased by β-ionone with concomitant increases in cAMP, pCREB, and synaptic proteins. Notably, opsin stimulated sprouting only when mislocalized to the plasmalemma of the rod cell body. CONCLUSIONS cAMP causes neuritic sprouting in rod, but not cone, cells through the AC-PKA-CREB pathway known to be associated with synaptic plasticity. We propose that in retinal disease, mislocalized rod opsin gains access to cAMP signaling, which leads to neuritic sprouting.
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Affiliation(s)
- Jianfeng Wang
- Department of Neurology and Neuroscience, New Jersey Medical School–University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103, USA
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Costa ACS, Stasko MR, Schmidt C, Davisson MT. Behavioral validation of the Ts65Dn mouse model for Down syndrome of a genetic background free of the retinal degeneration mutation Pde6b(rd1). Behav Brain Res 2009; 206:52-62. [PMID: 19720087 DOI: 10.1016/j.bbr.2009.08.034] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 08/22/2009] [Accepted: 08/27/2009] [Indexed: 02/03/2023]
Abstract
The Ts65Dn mouse is the most studied and complete aneuploid model of Down syndrome (DS) widely available. As a model for human trisomy 21, these mice display many attractive features, including performance deficits in different behavioral tasks, alterations in synaptic plasticity and adult neurogenesis, motor dysfunction, and age-dependent cholinergic neurodegeneration. Currently, Ts65Dn mice are maintained on a genetic background that leads to blindness in about 25% of their offspring, because it segregates for the retinal degeneration 1 (Pde6b(rd1)) mutation of C3H/HeSnJ. This means that 25% of the mice have to be discarded in most experiments involving these animals, which is particularly problematic because the Ts65Dn stock has low reproductive performance. To circumvent this problem, we have bred the Ts65Dn extra chromosome many generations into a closely related genetic background that does not carry the Pde6b(rd1) mutation. Although the new genetic background is expected to be nearly identical to the original, differences in genetic background have the potential to alter mouse performance in certain behavioral tests. Therefore, we designed the present study primarily as a behavioral validation of Ts65Dn mice of the new background. We compared side-by-side their performance with that of Ts65Dn mice of the original background on the following set of assessments: (1) body length and weight; (2) 24-h locomotor activity; (3) the Morris water maze; (4) fear conditioning; and (5) grip strength. Except for very subtle differences on water maze performance, we found no significant differences between Ts65Dn mice on the two backgrounds in the measures assessed.
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Affiliation(s)
- Alberto C S Costa
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA.
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12
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Errijgers V, Van Dam D, Gantois I, Van Ginneken CJ, Grossman AW, D'Hooge R, De Deyn PP, Kooy RF. FVB.129P2-Pde6b(+) Tyr(c-ch)/Ant, a sighted variant of the FVB/N mouse strain suitable for behavioral analysis. GENES BRAIN AND BEHAVIOR 2006; 6:552-7. [PMID: 17083330 DOI: 10.1111/j.1601-183x.2006.00282.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mice of the FVB/N strain are severely visual impaired as a result of tyrosinase gene defects, leading to a deficiency of the key enzyme for melanin synthesis in skin and eye and of cyclic guanosine monophosphate phosphodiesterase gene defects, which results in albinism (Tyr(c/c)) and retinal degeneration (Pde6b(rd1/rd1)), respectively. Nevertheless, FVB/N mice are commonly used for the generation of transgenic animals because of their large, strong pronuclei and high breeding performance. However, due to visual impairment of the FVB/N animals, the resulting transgenic animals cannot be used in tests that depend on vision, including tests of cognitive behavior. Therefore, we have bred a sighted version of the FVB/N strain by an outcross between FVB/N and 129P2/OlaHsd, followed by repeated backcrosses to FVB/N mice while selecting against albinism and homozygosity of the retinal degeneration mutation. After 11 generations of backcrossing, sighted animals were intercrossed to generate the congenic FVB.129P2-Pde6b(+) Tyr(c-ch)/Ant strain, which is pigmented (Tyr(c-ch)/(c-ch)) and devoid of the genetic predisposition to retinal degeneration. The accurate visual abilities of the FVB.129P2-Pde6b(+) Tyr(c-ch)/Ant mice, for which we propose the name FVBS/Ant, demonstrated a clear visual evoked potential in the presence of normal eye histology and improved performance in the Morris water maze test.
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Affiliation(s)
- V Errijgers
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
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13
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Abramow-Newerly W, Lipina T, Abramow-Newerly M, Kim D, Bechard AR, Xie G, Clapcote SJ, Roder JC. Methods to rapidly and accurately screen a large number of ENU mutagenized mice for abnormal motor phenotypes. ACTA ACUST UNITED AC 2006; 7:112-8. [PMID: 16753976 DOI: 10.1080/14660820500443000] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In a dominant genetic screen for late-onset motor impairments in mice, 16-20-week-old N-nitroso-N-ethylurea (ENU)-mutagenized females were subjected to a behavioural test battery consisting of a visual assessment followed by the vertical pole, rotarod and grip strength tests. SOD1-G93A transgenic mice were tested in parallel as a positive control to provide information on the validity and sensitivity of the screen. From among the 1500 G1 ENU mice screened, four affected mice with impaired motor function were classified as outliers. Approximately 32% of the G2 and G3 progeny of one outlier were affected. Vertical pole, rotarod and grip strength test scores were significantly correlated with each other and with body weight in the G1 progeny, but the correlation with body weight was not maintained in the G2 and G3 progeny. We found that two tests, tail suspension and vertical pole, were sufficient to distinguish ENU outliers and SOD1-G93A hemizygotes from control mice, and could detect abnormalities earlier and more frequently than the other tests employed.
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Affiliation(s)
- Wanda Abramow-Newerly
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada.
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14
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Clapcote SJ, Lazar NL, Bechard AR, Roder JC. Effects of the rd1 mutation and host strain on hippocampal learning in mice. Behav Genet 2006; 35:591-601. [PMID: 16184487 DOI: 10.1007/s10519-005-5634-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Accepted: 05/09/2005] [Indexed: 10/25/2022]
Abstract
Many of the inbred mouse strains commonly used in biomedical research are homozygous for the rd1 mutation of the Pde6b gene, which causes retinal degeneration. To dissociate the behavioural effects of rd1 homozygosity from those of the genetic background of the host strain in the most widely used paradigms for evaluating the cognitive abilities of mice, two rd1 homozygous strains (C3H/HeJ and CBA/J) were compared with two Pde6b wild-type strains, each possessing a genetic background identical (C3A.BLiA-Pde6b+/J) or very similar (CBA/CaJ) to that of its rd1 homozygous relative. In the fear conditioning procedure, the presence of the rd1 mutation had no effect on performance at any stage, as the superior contextual learning of the CBA/J and CBA/CaJ strains could be explained by genetic background effects alone. In the Morris water maze, only the Pde6b wild-type C3A.BLiA-Pde6b+/J and CBA/CaJ strains were able to demonstrate spatial learning. The study thus demonstrates how retinal degeneration and genetic background have different effects in these two tests of hippocampus-dependent learning and memory.
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Affiliation(s)
- Steven J Clapcote
- Mount Sinai Hospital Research Institute, Room 860, 600 University Avenue, Toronto, Ontario, M5G 1X5, Canada.
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15
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McFadyen MP, Kusek G, Bolivar VJ, Flaherty L. Differences among eight inbred strains of mice in motor ability and motor learning on a rotorod. GENES, BRAIN, AND BEHAVIOR 2003; 2:214-9. [PMID: 12953787 DOI: 10.1034/j.1601-183x.2003.00028.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The rotorod is commonly used to assess motor ability in mice. We examined a number of inbred strains to determine whether there is genetic variability in rotorod performance and motor learning. Mice received three trials per day for three days in a modified accelerating rotorod paradigm, and active rotation performance was calculated for each day. Male and female 129S1/SvlmJ, A/J, BALB/cByJ, C3H/HeJ, C57BL/6J, CBA/J, DBA/2J and FVB/NJ mice were tested. Strain and sex differences were observed in motor performance. Motor learning also differed across strains, as some strains showed an improvement in performance over the three days while other strains did not. In certain strains the weight and body length of the mouse correlated with rotorod performance. The role of vision in motor performance on the rotorod was assessed by a comparison of C3H/HeJ mice (with retinal degeneration) and congenic C3A.BLiA-Pde6b+ (Pdeb+) mice (without retinal degeneration). The sight-impaired C3H mice stayed on the rotorod longer than did their sighted Pdeb+ partners, although both strains improved across days. Thus, we have demonstrated a genetic component in rotorod performance, and we have shown that factors other than inherent motor ability can contribute to rotorod performance in mice.
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Affiliation(s)
- M P McFadyen
- Genomics Institute, Wadsworth Center Jordan Road, Troy, New York 12180, USA
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16
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Rothermel A, Layer PG. Photoreceptor plasticity in reaggregates of embryonic chick retina: rods depend on proximal cones and on tissue organization. Eur J Neurosci 2001; 13:949-58. [PMID: 11264667 DOI: 10.1046/j.1460-9568.2001.01469.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Plasticity of photoreceptors and their integration into epithelial structures homologous to an outer nuclear layer (ONL), was investigated in embryonic chick retinal cell reaggregates by immunohistochemistry using an antibody specific for red plus green cones (RG-cones) and an antibody for rods. If reaggregates are raised in the presence of pigmented epithelium (RPE), completely reconstructed, stratified retinal spheres are produced, where all rods and cones are integrated into an outer laminar ONL, similar to a normal retina. In the absence of RPE, 'rosetted' spheres form which contain internal rosettes homologous to an ONL. Only a minor fraction of cones and rods of 'rosetted' spheres are located within rosettes, while a larger fraction is diffusely displaced in nonorganized areas, thus, not contributing to an ONL-like epithelium. In both types of spheres, the total percentage of RG-cones was similar to the in vivo retina, indicating that expression of cones is autonomous. Following cones, after about one day, rods developed only within already existing RG-cone clusters. Thereby, the ratio of rods to RG-cones increases as the tissue organization decreases: for stratified spheres this ratio is, 0.50 (1 rod/2 cones; similar to mature retina); for rosettes, 0.74 (3 rods/4 cones) and for nonorganized areas, 1.09 (1 rod/1 cone) -- a higher ratio under our conditions has never been detected. Thus, rod expression depends strictly on the presence of nearby cones; their relative numbers are distinctively adjusted according to the cytoarchitecture of the tissue environment. The biomedical implications of these findings are briefly discussed.
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Affiliation(s)
- A Rothermel
- Darmstadt University of Technology, Developmental Biology & Neurogenetics, Schnittspahnstrasse 3, D-64287 Darmstadt, Germany
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17
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Intraocular gene transfer of ciliary neurotrophic factor prevents death and increases responsiveness of rod photoreceptors in the retinal degeneration slow mouse. J Neurosci 1998. [PMID: 9801367 DOI: 10.1523/jneurosci.18-22-09282.1998] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Several mutations causing both photoreceptor degeneration and malfunction have been identified in humans and animals. Although intraocular injection of trophic factors has been shown to reduce photoreceptor death in a few conditions of rapid photoreceptor loss, it is unclear whether long-term beneficial changes in functional properties of affected photoreceptors can be obtained by treatment with these factors. The rds/rds mouse is a spontaneous mutant bearing a null mutation in the rds/peripherin gene, which is linked to many forms of dominant retinal degenerations in humans. Here, we report that intraocular adenovirus-mediated gene transfer of ciliary neurotrophic factor (CNTF) in this mutant reduces photoreceptor loss, causes a significant increase in the length of photoreceptor segments, and results in a redistribution and an increase in the retinal content of the photopigment rhodopsin. These effects are accompanied by a significant increase in the amplitude of the a- and b-waves of the scotopic electroretinogram. These results suggest that continuous administration of CNTF could potentially be useful for the treatment of some forms of retinal degeneration.
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18
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Rothermel A, Willbold E, Degrip WJ, Layer PG. Pigmented epithelium induces complete retinal reconstitution from dispersed embryonic chick retinae in reaggregation culture. Proc Biol Sci 1997; 264:1293-302. [PMID: 9332014 PMCID: PMC1688576 DOI: 10.1098/rspb.1997.0179] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Reaggregation of dispersed retinal cells of the chick embryo leads to histotypic retinospheroids in which the laminar organization remains incomplete: photoreceptors form rosettes which are surrounded by constituents of the other retinal layers. Here, for the first time, a complete arrangement of layers is achieved in cellular spheres (stratoids), provided that fully dispersed retinal cells are younger than embryonic day E6, and are reaggregated in the presence of a monolayer of retinal pigmented epithelium (RPE). A remarkable mechanism of stratoid formation from 1 to 15 days in vitro is revealed by the establishment of a radial Müller glia scaffold and of photoreceptors. During the first two days of reaggregation on RPE, rosettes are still observed. At this stage immunostaining with vimentin and F11 antibodies for radial Müller glia reveal a disorganized pattern. Subsequently, radial glia processes organize into long parallel fibre bundles which are arranged like spokes to stabilize the surface and centre of the stratoid. The opsin-specific antibody CERN 901 detects photoreceptors as they gradually build up an outer nuclear layer at the surface. These findings assign to the RPE a decisive role for the genesis and regeneration of a vertebrate retina.
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Affiliation(s)
- A Rothermel
- Department of Developmental Biology and Neurogenetics, Darmstadt University of Technology, Germany
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19
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Layer PG, Rothermel A, Hering H, Wolf B, deGrip WJ, Hicks D, Willbold E. Pigmented epithelium sustains cell proliferation and decreases expression of opsins and acetylcholinesterase in reaggregated chicken retinospheroids. Eur J Neurosci 1997; 9:1795-803. [PMID: 9383202 DOI: 10.1111/j.1460-9568.1997.tb00746.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated the effect of the retinal pigmented epithelium on cell proliferation and differentiation in rosetted retinospheroids, which are retina-like spheres reaggregated in the complete absence of retinal pigmented epithelium from dissociated retinal cells of 6-day-old chick embryos in a rotation culture system. In spheroids raised in the absence of retinal pigmented epithelium (controls), acetylcholinesterase was expressed in cells of an inner nuclear-like layer and their neuropil matrices. Moreover, the ratio between rods and cones was found to be approximately normal throughout the spheroid. When spheroids were cultured in the presence of retinal pigmented epithelium monolayers, cell proliferation in spheroids as determined by BrdU labelling was significantly increased and extended for 1 week, while acetylcholinesterase protein levels and specific activities in homogenates were decreased to approximately 30%. At the same time, opsin immunoreactivity was completely suppressed within the spheroid and appeared slowly in cells around its periphery; i.e. the proportion of rhodopsin-positive cells decreased from 14 to 3%. This study reveals that the retinal pigmented epithelium in vitro sustains cell proliferation but inhibits the differentiation of acetylcholinesterase-positive cells and of photoreceptors.
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Affiliation(s)
- P G Layer
- Darmstadt University of Technology, Institute for Zoology, Germany
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20
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Hofs HP, Wagener DJ, De Vos D, Ottenheijm HC, Winkens HJ, Bovee PH, De Grip WJ. Antitumour activity and retinotoxicity of ethyldeshydroxy-sparsomycin in mice. Eur J Cancer 1995; 31A:1526-30. [PMID: 7577083 DOI: 10.1016/0959-8049(95)00246-f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The colony formation in agar of human tumour xenografts was used as a test system to study the cytostatic activity of ethyldeshydroxy-sparsomycin (EdSm) at the cellular level. EdSm was additionally studied in vivo in human tumour xenografts and murine tumour models. EdSm showed a clear dose-response effect in vitro. At continuous exposure with 0.01 micrograms/ml, 2 out of 11 of the tumours responded (a gastric and a small cell lung carcinoma). At 0.1 mu/ml EdSm, the tumour response was 5/11 tumours and at 1 microgram/ml the compound was active in all tumours. The maximal tolerable doses of EdSm in vivo have been determined in non-tumour bearing CDF1 mice. In the intraperitoneally (i.p.) given multiple dose schedules the respective LD10 doses indicated that the tolerable cumulative dose increases when lower doses are given more frequently. This also enhances the antitumour activity in L1210 leukaemia to 172% T/C. On the other hand, continuous infusion strongly diminished the tolerable dose as well as the antitumour activity. EdSm was also active against i.p. inoculated P388 leukaemia (150% T/C), B16 melanoma (156% T/C), and RC carcinoma (197% T/C), and the subcutaneously (s.c.) inoculated L1210 (139% T/C) and RC (138% T/C). Absence of tumour responses was found in the following s.c. implanted murine tumours: M5076 sarcoma, osteosarcomas C22LR and CP369, and the LL carcinoma, as well as in the human tumour xenografts: LXFG 529, a non-small cell lung carcinoma; GXF 251, a gastric carcinoma; and FMa, an ovary carcinoma. Possible long-range retinotoxic effects of EdSm were investigated in tumour-bearing mice, cured after surviving treatment with LD50 doses of EdSm, by assaying the protein biosynthetic capacity of the retinal by assaying the ocular rhodopsin and opsin levels as parameters. In none of these cases could a significant reduction in either opsin or rhodopsin levels be measured and no changes were seen histologically.
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Affiliation(s)
- H P Hofs
- University of Amsterdam, Laboratory of Radiobiology, The Netherlands
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21
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Chapter 11 Synaptic growth in the rod terminals after partial photoreceptor cell loss. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0278-4327(93)90012-i] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Jansen HG, Sanyal S. Synaptic plasticity in the rod terminals after partial photoreceptor cell loss in the heterozygous rds mutant mouse. J Comp Neurol 1992; 316:117-25. [PMID: 1573048 DOI: 10.1002/cne.903160110] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the retina of mice heterozygous for the retinal degeneration slow gene (rds/+) the photoreceptor cells, both rods and cones, develop abnormal outer segments but establish normal synaptic contacts. The other retinal layers also show normal structural organization. Starting from the age of 2 months, a very slow loss of photoreceptor cells progresses throughout life. As a result, the photoreceptor cell population in the retina of the affected mice is reduced to less than half at the age of 9-18 months. In some of the surviving rod terminals during this period, an increase in the number of synaptic ribbons is recorded. At the same time, the profiles of processes originating from the second order neurons and participating in these synapses are also increased in number so that the multiple ribbons appear as centres of multiple synaptic sites. Morphometric measurements of the perimeter of the synaptic profiles in rod terminals show a significant increase in the rds/+ retina over that of the control retina. Observations based on serial electron microscopy indicate that multiple synaptic sites are developed while the number of the second order neuronal processes, entering the terminals, remains unchanged. The frequency of terminals with multiple synapses in the rds/+ retina increases with progressive photoreceptor cell loss. Similar changes do not occur in the terminals of the cones. It is postulated that loss of some rod photoreceptor cells within a group that is presynaptic to common bipolars or horizontal cells results in partial deafferentation which in turn stimulates the growth of the remaining synaptic elements. The possible compensatory effect and functional significance of such synaptic growth are discussed.
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Affiliation(s)
- H G Jansen
- Department of Anatomy, Faculty of Medicine, Erasmus University, Rotterdam, The Netherlands
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Photoreceptor peripherin is the normal product of the gene responsible for retinal degeneration in the rds mouse. Proc Natl Acad Sci U S A 1991; 88:723-6. [PMID: 1992463 PMCID: PMC50885 DOI: 10.1073/pnas.88.3.723] [Citation(s) in RCA: 211] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Retinal degeneration slow (rds) is a retinal disorder of an inbred strain of mice in which the outer segment of the photoreceptor cell fails to develop. A candidate gene has recently been described for the rds defect [Travis, G. H., Brennan, M. B., Danielson, P. E., Kozak, C. & Sutcliffe, J. G. (1989) Nature (London) 338, 70-73]. Neither the identity of the normal gene product nor its intracellular localization had been determined. We report here that the amino acid sequence of the bovine photoreceptor-cell protein peripherin, which was previously localized to the rim region of the photoreceptor disk membrane, is 92.5% identical to the sequence of the mouse protein encoded by the normal rds gene. The differences between the two sequences can be attributed to species variation. Monoclonal antibodies were used with Western blot analysis to localize the wild-type mouse peripherin/rds protein to isolated mouse rod outer segments and to show that it, like bovine peripherin, exists as two subunits linked by one or more disulfide bonds. The relative amounts of peripherin/rds protein and rhodopsin in retinal extracts of normal and rds mutant mice were also compared. Identification of peripherin as the protein encoded by the normal rds gene and its localization to membranes of rod outer segments will serve as a basis for studies directed toward defining the role of this protein in the morphogenesis and maintenance of the outer segment and toward understanding the mechanism by which the rds mutation causes retinal degeneration.
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Jansen HG, Aguirre GD, van Veen T, Sanyal S. Development and degeneration of retina in rds mutant mice: ultraimmunohistochemical localization of S-antigen. Curr Eye Res 1990; 9:903-11. [PMID: 2147137 DOI: 10.3109/02713689008999562] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the developing photoreceptor cells of the homozygous rds mutant mice S-antigen is localized over the ciliary protrusion as in the control mice, and to a lesser extent over the inner segments, perikaryal cytoplasma and the cell terminals. As the outer segments develop in the normal retina, the discs become increasingly immunoreactive. In the rds/rds retina the outer segments fail to develop but small membrane bound vesicles, immunoreactive for S-antigen are extruded and phagocytized by the retinal pigment epithelium. In the retina of older mutant mice, as the photoreceptor cells degenerate slowly, the surviving cells continue to show persistent immunoreactivity for S-antigen in the different regions of the photoreceptor cells. In the heterozygotes the outer segments are reduced and appear abnormal, but the localization of S-antigen is similar to normal. In the receptor region of the normal retina and in the deviant membranous structures in the mutant retina the localization of S-antigen is similar to that of opsin. However, some differences in the subcellular localization of these two photoreceptor specific proteins have been observed. It is concluded that the rds gene acts subsequent to the synthesis of these proteins and possibly at the site of disc assembly.
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Affiliation(s)
- H G Jansen
- Department of Anatomy, Erasmus University, Rotterdam, The Netherlands
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